What cat food do you use?

Just curious what food you buy and why. We have 2 cats. Mr. Kitty (6y) is an indoor/outdoor kitty. He doesn't like anything other than plain dry food. Lulu (1y) is indoor only and will eat the dry cat food (Meow Mix) or wet (Fancy Feast). I am wanting to switch them both to a possibly healthier one, but also don't know if that is really a thing.